Dyestuffs of the tartrazine series



Patented May 31, 1932 EUG-EN BOMIG AND KARL HOLZACH, OF LUDWIGSHAFEN-ON-THE-RHINE; GERMANY,

ASSIGNORS T0 GENERAL ANILINE WORKS, INC., OF NEXV YORK, N. Y., A. CORPOR'A- TI.

TION OF DELAFNABE DYESTUFFS OF THE TARTRAZINEZ SERIES' No Drawing. Application filed October 10, 1930, Serial N0..487,899, and in Germany October 22, 1929.

The present invention, relates to new dyestuffs of the tartra-Zine series and process of producing the same- We have found that the dyestuffs of the tartrazine'series corresponding tothe general formula: a

X-N=NCG E ii in which X stands for the radicle S031 s V SOSH which may be further substituted are valuable dyestufis in View of the particularly greenish yellow shades obtained therewith. This valuable property is especially remarkable with the dyestuffs of the said kind in which the second sulphuric acid groups in the phenyl radicles are attached to the 2- or 3-positions, or to the Gt-positions in case the phenyl fadicle contains a methyl group. In View of their shades and their fastness to water they are particularly suitable for printing on paper and similar substrate, that is for graphic printing purposes. In addition thereto the new dyestuffs have other valuable properties. Thus the dyestuif containing a Q-methylphenyll.5-disulphonic acid radicle in the form of its colour lakes is particularly suitable for the wall paper industry, and these colour lakes have the further advantage of being fast to ov'erprinting. On the other hand, the dyestuff containing a phcnyl-3.5- disulphonic acid radicle and still more that containing a phenyl-Q.5-disulphonic acid radicle are particularly fast to light and are therefore most suitable for dyeing wool.

The preparation. of thesenew dyestuffs is carried out by condensing 1 molecular proportion of sodium dihydro-Xy-tartrate with 2 molecularproportions of a phenyl hydrazine- 5-sulphonic acid containing a further sulpho group preferably inthe 2- or 3-position, or by coupling a pyrazolone carboxylic acid or an alkyl ester thereof obtainable in the manner already known from oXalacetic ester by condensation with 1 molecular proportion of a phenyl hydrazine disulphonic acid, with a phenyl diazonium compound containing 2 sulpho'groups, the reacting, components being chosen that one of the sulpho groups is present. in the 5-position of the phenyl radicles. The resulting dyestuffs, in spite of the numerous sulphonic acid groups present in the molecule, may be readily salted out from their solutions. I

The colour lakesof the dyestuffs are obtainable according to known methods by precipitating the dissolved dyestuffs by means of salts of the alkaline earth metals.

The following examples will further illustrate thenat-ure of this invention, but then]- vention is notrestricted to these examples. The parts are by Weight.

Example 1 The dyes-tuft dyes wool power by treatment with metal salts and the v like.

Eammple 2 The same dyestuff as is described in Example 1 is obtained by coupling in aqueous solution 145 parts of the 1(phenyl3'.5 -disulphonic a c i d )-5-pyrazolone-8-carboxylic acid (prepared by condensation of oxalacetic ethyl ester with phenyl hydrazine-3.5-disulphonic acid and saponifying the product) with the diazonium compound prepared in the usual manner from 100 parts of aniline- 3.5-disulphonic acid. The resulting dyestufi' is isolated in the usual manner by salting out.

A similar dyestuif is obtained by employing in the aforedescribed reaction the 1- (phenyl-3.5-disulphonic a ci d )-5-pyrazo lone-3-carboxylic acid ethyl ester.

Example 3 198 parts of phenyl hydrazine-2.5-disulphonic acid are stirred into 2000 parts of 25 per cent sulphuric acid and are heated to 95 C. At the same temperature, 100 parts of sodium dihydroxy-tartrate are slowly introduced into the solution, the solution is kept at 95 C. for some hours and the resulting dycstuff is salted out in the usual manner. The precipitated dyestufi' is worked up in the usual manner. The dyestuff obtained has similar properties to the dyestuf'f described in Example 1.

E wample j;

Eazample 5 Colour lakes of the dyestuff described in the foregoing examples may be prepared as follows:

20 parts of aluminium sulphate containing 18 per. cent of aluminium oxide are dissolved in 200 parts of water and mixed with a solution of 10 parts of calcined soda in 100 parts of water. The precipitate is washed with water after decanting and mixed with a solution of 3.5 parts of stannic chloride in 35 parts of water and boiled for hour. Thereupon, 4: parts of a dyestufi in 200 parts of water are added and 10 per cent solutions of 8.5 parts of barium chloride, 4.4 parts of 1.seo,47s

aluminium sulphate and 2.5 parts of calcined soda are introduced one after the other into the mixture. The precipitate is then filtered ofl', pressed, dried and ground.

What we claim is 1. As new articles of manufacture dyestuffs of the tartrazine series corresponding to the general formula:

in which X stands for the radicle:

SOzH

which may be further substituted by a methyl group, and in which the hydrogen atoms of the acid groups may be replaced by ions of an alkaline earth metal.

2. As a new article of manufacture the dyestuff of the tartrazine series corresponding to the formula:

dyeing wool greenish yellow shades.

3. As a new article of manufacture the dyestufl' of the tartrazine series corresponding to the formula:

dyeing wool greenish yellow shades.

In testimony whereof we have hereunto set our hands.

EUGEN ROMIG. KARL HOLZACH. 

